Synchronizing arrangement for moving-picture projectors



Oct. 29, H329. D. B. PERRY A SYNCHRONIZING ARRANGEMENT FOR MOVING PICTURE PRoJEcToRs Filed Nov, 21, 1925 A TTORNEY Patented Oct. 29, 1929 UNITED sra'rss.

.PATENT ol-FlclsI DONALD B. PERRY, OF YONKERS, NEW YORK, ASSIGNOR TO AMERICAN TELEPHONE AND TELEGRAPE COMPANY, A CORPORATION F NEW YORK t SY'NHBONIZING ARBANGEMENT FOR MOVING-PICTURE PROJECTORS Application tiled November 21, l1925. Serial Nia-70,611.

The invention relates to control apparatus for moving picture machines and more specifically to arrangements for providing synchronous operation of a plurality of moving picture machines;

The arrangements of the invention would he particularly useful under conditions when tor mechanism machines.

In Figs. 1 and 2, the arrangements at theleft of .the dotted line XY represent the con- V trolling station where the s eaker is located.

- K it would be desirable to give similar exhibitions of a visual and audible type simultaneously at a plurality of places. For examle, with the arrangements of `the invention 1t would be possible to have the same orchestra furnish music at several moving picture houses at once. Furthermore, a lecturer might be accom anied by a moving picture film and with t e arrangements of this invention present his exhibition to several audiences at once. Other features and objects A of the invention will appear more fully rom The arrangements at the rlght of line XY represent one of any desired number of distant connected stations. The two stations illustrated, are interconnected by two telephone circuits, such as line L, for the voice or music, and by the line L2 for synchronizing, automatic starting and operatorss communication. These two telephone circuits L1 and L2 are shown as of' the metallic type but it is understood that they may consist of line, radio or carrier channels, or any desired combination of these. The circuits L8 and L shown in dotted lines would be provided, as well as other similar circuits, should it be desired to connect with other stations.

The motion picture projecting machines at the various stations are driven by apparatus shown in Fig. -3 consisting of a motor 32 and fly Wheel 31. To the left of the motor and controlled by a magnet is a clutch 33. Connected -to-the clutch is an idler gear and the' mechanism 34 which makes vit possible to 'orient the driving gear in respect to the motor. trated as135.j

The motor 'used is 'the well known phonic wheel motor. The circuit details of the motor may be seen by reference to the diagram of motor 12 of Fig. 2. The motor l2 is operated in the usual manner by the driving tuning fork 13. This fork is operated at its own-natural frequency, the speed of vibra- The driving gear mechanism is illus- .v

tion depending upon the fork Weights hung i on the tines. As the fork 13 vibrates, an auxiliary Contact 14 on the fork will periodically close a shunt circuitfl across the output of the speedcontroloscillator 10. This oscillator generates a train of oscillations of a desirable frequency,'such for example, as 350 cycles per second. If We assume for purposes of illustration that the period of vibration of the fork 13- is approximately 50 cycles per second, this will result in spurts of 350 cycles per second alternations being sent out from the oscillator 10 at the rate of 50 spurts per second. The low pass filter 11 will pass these spurts of 35() cycle current and they will be transmitted over line L2, through the low pass filter 29, to the amplifier detector 30, and thence to the operating windings of relay 28. This relay will accordingly open and close its contacts with each spurt of current, or at the same rate as the period of vibration of fork 13, namely, 50 times a second. 'lhis will open and close the circuit l() at the rate of 50 times per second and operate the fork magnet 41 at this frequency. Accordingly, the driving fork 26 will operate at a frequency which willl be the same as the4 master fork 13. As the fork 26 drives the motor 25 and since both the forks 26 and 13 operate at exactly the same frequency, the motors 12 and 25 will operate in synchronisin at the same speed.

At all times, except when the various movstarted, the operators of the machines may communicate with each other over a telephone circuit. This telephone circuit comprises the o rators set 8, the switching device 7, the Iter 9 which passes frequencies above 400 cycles line L2, the filter 18, switch 19, and the telephone set 20. This circuit will pass frequencies above 400 cycles which will allow understandable speech to be transmitted.

The operation of starting the machines is as follows: The fork 13 and motor 12 at the controlling station will first be started with the clutch mechanism 16 released to revent feeding of the film. The films at al of the stations having been threaded to the starting point and each operator having informed over the heretofore mentioned telephone circuit the operator at the controlling station that he is ready, the starting key 7 will be thrown to the right. This will connect the starting oscillator 6, which generates oscillations of a frequency of 1,000 cycles, to the lineLz. This puts a 1,000 cycle tone on the circuit. All of the other operators upon hearing this note, will throw their starting keys, such as the ke 19. This will connect the line L2 to the amp ier detector 21. The rectified 1,000 cycle current will then operate the relay 22 and cause it to hold its armature on the right-hand or marking contact, thus holding open circuit 44. The ke 23 will also be restored at this time from t e-upward position to the middle position to prepare completion of the circuit 44 to the clutch mechanism 24.

The operator at the control station now presses the start key 5 to operate all of the clutches and thus start all of the film projecting machines operating in the following manner. The left-hand contact of key 5 closes a circuit from battery over circuit 42 to operate the clutch mechanism 16. This mechanism may be held operated by a locking circuit 45, which ma be opened later by the release key 17. The right-hand contact of key 5 closes a short circuit 43 across the output of the starting oscillator 6 and thus cuts off the 1,000 cycle tone on line L2. This will cause all of the relays similar to relay 22, to release. The release of relay 22 will cause its contact to close to its left-hand contact. This willy close circui-t 44 and operate the clutch mechanism 24. The operators at all of the distant stations may restore their keys, such as key 19, to the normal position as soon v as film is started,and also operate their keys,

` position keeps the clutch such as key 23 to the lower position. The controlling operator will also restore his key 7 to normal. This a ain makes telephone communication possib e .between the projecting machine operators. -Key 23-in the lower operated.

It is pointed out that the films at all of the stations should be identical and that any patching or splicin made in one should be duplicated in the ot ers. The loud s eaker circuit is shown in schematic form in ig.,1. A microphone 1 and an amplifier 2 are located at the controlling station and an amplifier 3 and loud speaker 4 at each distant station.

While the invention has been disclosed in certain specific forms which are deemed desirable, it is understood that it is capable of embodiment in many other widely varied forms without departing from the spirit of the invention as defined in the appended claims.

What is claimed is:

1. Synchronizinv' andcontrol arrangements for a plura ity of visual and audi le exhibitions comprising a line circuit2 a master station connected to said circuit, said master station comprising a. motor driving mechanism for a moton icture machine, a vibrating driving fork or operating said mxotor, a circuit controlled by the frequenc of vibration of said ldriving fork for app ying to said line circuit a series of pulses of the same periodicity as the frequency of said fork virations, a second station connected to said line circuit comprising a motor driving mechanism for a motion picture machine, a vibrating driving fork for operatin said motor, an operating circuit for said for controlled b said incoming pulses whereby said forkw' l vibrate with the same periodicity as the frequency of said driving fork at said master station, starting mechanism for each of said motor driving mechanisms, and means associated with said line -circuit at one of said stations for simultaneously operating said starting mechanisms. s

2. A control circuit interconnecting two stations, motor driving mechanism for a motion picture machine at each station, vibrating driving forks for each of said motors, means associated with said control circuit at each of said stations and Acontrolled by the frequency of vibration of the fork at one stameans associated with said control circuit at/ each of said stations and controlled by -the frequency `of vibration of the fork at one station for controllin the frequency of vibration of the fork at t e other station, clutch mechanisms for each of said motor drivin mechanisms, relay means associated withsai relay means, and means at the other of said stations for applying to said control circuit oscillations of .a esired frequency to operate said relay means and for operating the clutch mechanism at said last mentioned station.

In testimony whereof, I have signed my name to this specification this 19th day of i November i925.

DONALD B. PERRY.

DISCLABMER 1,733,165-Donald B. Perry, Yonkers, N. Y. SYNCHRONIZING ARRANGEMENT son MOVING-PICTURE PnoJncToRs. Patent dated October 29, 1929. Disclaimer filed March 28, 1930, by the assignee, American Telephone and Telegraph Company. Hersh enters this disclaimer to the said claims of said Letters Patent which are in the fo lowing words-to wit: I i

2. A control circuit interconnecting two stations, motor driving mechanism for a motion picture machine at each station, vibrating driving forks for each of said motors,

. means associated with said control circuit at each of said stations and controlled by the frequency of vibration of the fork at one station for controlling the frequency of vibration of the fork at the other station, starting mechanism for each of said motor driving mechanisms, and means associated with said control circuiti at one of said stations for simultaneously operating said starting mechanisms. l

3, A control circuit interconnecting two stations, motor driving niechanism for a motion picture machine at each station, vibrating driving .forks for each of said motors, `means associated with said control circuit at each of said stations and controlled by the frequencyof vibration of the fork at one station for controlling the frequency4 of vibration of the fork at the other station, clutch mechanisms for each of said motor driving mechanisms, rela means associated with said control circuit at one of said stations tuned to respon to oscillations of a desired frequency, an operating circuitfor the clutch mechanism at said station controlled hy said relay means, andmeans at the other of said stations for applying to said control circuit oscillations of a desired freuency to operate said relay means and for operating the clutch mechanism at sai last ymentioned station.

[Oficial Gazette- April 15, 1.980.] 

